The present invention relates to novel uses in foodstuffs and in food-stuff flavors of 3,5-di-(2-methylpropyl)-1,2,4-trithiolane or cis or trans isomers thereof having the structures: ##STR3##
Artifical flavoring agents for foodstuffs have received increasing attention in recent years. In many areas, such food flavoring agents are preferred over natural flavoring agents at least in part because of the uniform flavor that may be so obtained. For example, natural food flavoring agents such as extracts, essences, concentrates and the like are often subject to wide variation due to changes in the quality, type and treatment of the raw materials. Such variation can be reflected in the end product and results in unreliable flavor characteristics and uncertainty as to consumer acceptance and cost. Additionally, the presence of the natural product in the ultimate food may be undesirable because of increased tendency to spoil. This is particularly troublesome in convenience and snack food usage where such products as dips, soups, chips, prepared dinners, canned foods, sauces, gravies and the like are apt to be stored by the consumer for some time prior to use.
The fundamental problem in preparing artificial flavoring agents is that of achieving as nearly as possible a true flavor reproduction. This generally proves to be a difficult task since the mechanism for flavor development in many foods is not understood. This is notable in products having roasted and smoked flavor characteristics, for example, roasted almond, roasted pork and smoked sesame flavor characteristics.
Reproduction of roasted, crisp bacon and pork rind flavors and aroms have been the subject of a long and continuing search by those engaged in the production of foodstuffs. The severe storage of foods, especially protein foods, in many parts of the world, has given rise to the need for utilizing non-meat sources of proteins and making such proteins as palatable and as meat-like as possible. Hence, materials which will closely simulate or exactly reproduce the flavor and aroma of roasted pork products are required.
Moreover, there are a great many meat containing or meat based foods presently distributed in a preserved form. Examples of these are condensed soups, dry-soup mixes, dry meat, freeze-dried or lyophilized meats, packaged gravies and the like. While the products contain meat or meat extracts, the fragrance, taste and other organoleptic factors are often impaired by the processing operation and it is desirable to supplement or enhance the flavors of these preserved foods with versatile materials which have either roasted pork or chip bacon-like or pork rind-like or "roasted" aroma and taste nuances.
In U.S. Pat. No. 3,863,013, it is disclosed that five or six numbered heterocyclo compounds having two sulfur atoms in the ring are useful to alter the flavor or aroma of foodstuffs. The di-thioheterocyclic compounds disclosed be suitable according to U.S. Pat. No. 3,863,013 are represented by the following formulae: ##STR4## and each of R.sub.1 to R.sub.4 is hydrogen or a lower alkyl radical of one to three carbon atoms. Most of these compounds are disclosed at column 2 and 3 of U.S. Pat. No. 3,863,013 to have beef, garlic, vegetable and onion-type aromas and tastes, thusly:
"1,3-Dithiolane having the structure ##STR5## is described in Meadow, J. R. et al., J.A.C.S., Vol. 56, p. 2177 (1934) and U.S. Pat. No. 2,690,988. It has a sweet, sulfury character, which in high levels becomes reminiscent of degrading onions. It is useful for its sulfur notes in chocolate and coffee and roasted garlic notes found in stews, jellied veal dish and gravies. Taste threshold level is 2 parts per billion (2 ppb).
2-Methyl-1,3-dithiolane having the structure ##STR6## is described in J. Chem. Soc., B, (1970), p. 404 at p. 407 and U.S. Pat. No. 2,690,988. It has a cooked, roasted onion character. The background notes are suitable for stewed vegetable and vegetable protein hydrolyzate type flavors. Its taste threshold value is 20 ppb.
3,5-Dimethyl-1,2-dithiolane having the formula ##STR7## is described in Schotte, L., Arkiv. Kemi., Vol. 9, p. 441 (1956). It has a cooked onion note developing into a cooked vegetable nutty note. Its taste threshold value is 10 ppb.
3-Methyl-1,2-dithiolane having the formula ##STR8## It has an oniony metallic taste with cooked beef or braised and vegetable nuances. It is suitable for stewed vegetable and braised beef flavors. Taste threshold level is 2 ppb.
2,4-Dimethyl-1,3-dithiolane having the structure ##STR9## is described by Leggeter B. E. et al. in Can. J. Chem., Vol. 41, No. 10, p. 2671 (1963). It has an onion-like taste with slight metallic background notes and is suitable for stewed vegetable flavors. Its taste threshold value is 20 ppb.
4-Methyl-1,3-dithiolane having the structure ##STR10## is generally described in U.S. Pat. No. 2,690,988. It has an oniony, root vegetable-like taste and is useful for stewed vegetable or braised beef type flavors. Its taste threshold value is 50 ppb.
1,2-Dithiane (ortho-dithiane) having the formula ##STR11## is described in Schoberl, A. Et al., Ann., Vol. 614, p. 66 (1958). It has a garlic character with slight metallic nuance and is suitable for stewed vegetable and horseradish flavors. Its taste threshold value is 2 ppb.
1,3-Dithiane (m-dithiane) having the formula ##STR12## and has been described by Meadow & Read in J.A.C.S., Vol. 56, p. 2177 (1934). It has an onion, garlic-like taste with a metallic by-note and is suitable for meat alium flavors. Its taste threshold value is 50 ppb.
1,4-Dithiane (p-dithiane) having the formula ##STR13## has been described in J. Chem. Soc., B, (1970), p. 404 at 407. It has an onion-like or garlic-like character and is useful for stewed vegetable type flavors. Its taste threshold value is 50 ppb.
2-Methyl-1,3-dithiane having the formula ##STR14## has been described by Autenreith, W. et al in Ber., 32, p. 1375 (1899). It has an onion-like character with metallic notes and is suitable for vegetable type flavors. Its taste threshold value is 20 ppb.
2,4-Dimethyl-1,3-dithiane having the formula ##STR15## is described by Eliel et al., in J.A.C.S. Vol. 91, No. 10, p. 2703 (1969). It has an allium-onion like character with slight metallic notes and is suitable for onion flavors. Its taste threshold value is 5 ppb.
4-Methyl-1,3-dithiane having the formula ##STR16## It has an onion, garlic and tomato like character and is suitable for stewed meats, gravy, tomato and onion flavors. It has a taste threshold level of 50 ppb.
2,4,6-Trimethyl-1,3-dithiane having the formula ##STR17## has been described by Eliel et al., J.A.C.S., 91, No. 10, p. 2703 (1969). It has a root vegetable-like character and is suitable for stewed vegetable or potato flavors. Its taste threshold level is 10 ppb."
Tetra and penta thiolane compounds are also disclosed for use in flavoring compositions for foodstuffs by U.S. Pat. Nos. 3,503,758 and 3,488,362. Thus, for example, in U.S. Pat. No. 3,503,758 compounds having the generic structure ##STR18## wherein X may be --CH.sub.2 --S--, --S--CH.sub.2 --, --CH.sub.2 --S--CH.sub.2 -- or --S--CH.sub.2 --S--
Specifically, the compounds: 1,2,3,5,6-pentathiepane (lenthionine); 1,2,3,5-tetrathiane; 1,2,4,6-tetrathiepane; and 1,2,4,5-tetrathiane indicated to be useful in, for example, enhancing pork and beef flavors.
A paper in Tetrahedron, Vol. 28, pages 3489-3500 (1972) entitled: "Synthesis of 3,5-Dialkyl-1,2,4-Trithiolanes/Assignment of Configuration and Conformational Analysis by PMR" by Tjan, Haakman, Teunis and Peer of the Unilever Research Duiven of the Netherlands discloses the synthesis of 3,5-dialkyl-1,2,4-trithiolanes of the structure: ##STR19## wherein R is disclosed to be either of methyl, ethyl, isopropyl or t-butyl. It is also disclosed by Tjan et al that such materials may be synthesized according to the technique of Asinger et al, Liebigs Ann. Chem. 627, 195 (1959).
Brinkman et al, J. Agr. Food Chem. 20, 177 (1972) during their investgiations in to components contributing to beef flavor isolated from beef broth two volitale isomers which were tentatively identified as 3,5-dimethyl-1,2,4-trithiolanes. In addition, Chang et al Chem. Ind. (London) 1639 (1968) isolated two isomeric 3,5-dimethyl-1,2,4-trithiolanes from boiled beef and suggested that the isomers were in "cis" and "trans" forms but made no structural assignment. In paragraph 2 of the Tjan et al article, it was stated:
"". . . It was necessary to synthesize compound I (3,5-dimethyl-1,2,4-trithiolane) and in view of the promising properties of the compounds as flavoring agents we investigated a more general synthesis for 3,5-dialkyl-1,2,4-trithiolanes . . .
Canadian Patent 623,330 discloses and claims 1,2,4-trithiolanes having the formula: ##STR20## wherein R.sub.1 is alkyl or hydrogen and R.sub.2 is alkyl, Specifically disclosed are 3,5-di-n-propyl-1,2,4-trithiolane and 3,5-diethyl-1,2,4-trithiolane.
However, nothing in the prior art including subject matter mentioned in the Tjan et al article or in Canadian Patent 623,330 suggests the synthesis and flavor use and flavor characteristics of the 3,5-di-(2-methylpropyl)-1,2,4-trithiolane or of its cis or trans isomers of our invention.